Frequencies for first 10,000 rows of rf_pdiab variable in natl2014 dataset :

Pre-pregnan |
cy Diabetes |
      Y Yes |      Freq.     Percent        Cum.
------------+-----------------------------------
          N |      9,778       97.78       97.78
          U |        128        1.28       99.06
          Y |         94        0.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 15 Jun 2016